2026-06-27T12:28:05Zhttps://docta.ucm.es/rest/oai/requestoai:docta.ucm.es:20.500.14352/587512023-08-28T06:43:58Zcom_20.500.14352_14col_20.500.14352_15
Docta Complutense
author
Dobado González, Antonio
author
Peláez Sagredo, José Ramón
2023-06-20T18:50:38Z
2023-06-20T18:50:38Z
1993-02
0170-9739
10.1007/BF01474345
https://hdl.handle.net/20.500.14352/58751
http://dx.doi.org/10.1007/BF01474345
http://link.springer.com
The direct chiral perturbation theory (ChPT) one-loop prediction for the production of two pions from two photons is compared with the recent Crystal Ball experimental data. The one-loop computation does not fit data even close to threshold because unitarity effects are important even at very low energies. However, when the constraints coming from unitarity and analyticity are included in a suitable way, the range of application of one-loop ChPT can be largely extended in agreement with the experiment.
Unitarity and gamma-gamma-]pi-pi in chiral perturbation-theory
journal article